/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicMeshOctree3.h
For a fixed-level cut set created by BuildLevelCutSet, check that all current cells at that level are in the cut set (call this after adding/removing to the tree to make sure the CutSet is up to date)
void UpdateLevelCutSet ( [FTreeCutSet](API\Runtime\GeometryCore\DynamicMesh\FDynamicMeshOctree3\FTreeCutSet) & CutSet, [TArray](API\Runtime\Core\Containers\TArray)< [FCellReference](API\Runtime\GeometryCore\DynamicMesh\FDynamicMeshOctree3\FCellReference) > & NewCutCellsOut ) const